Miniaturization of circuit patterns, low power consumption and high-speed operation of semiconductor devices proceed, and therefore low capacitance and low resistance of the circuit patterns are spread. As one means of ensuring high-speed and normal operation of the circuit, there has been considered to lower a dielectric constant of an interlayer insulating film.
An insulating film containing a carbon atom, such as an amorphous carbon film, an organic compound insulating film containing a fluorine atom, and an inorganic insulating film have drawn attention as an insulating film having a low dielectric constant. However, must satisfy the following requirements to become a substitute of a silicon oxide insulating film, which is most frequently employed at the present. That is, they must have:
1) Low dielectric constant, and also the following characteristics, which are basically required for a semiconductor insulating film: PA1 2) Good adhesion, PA1 3) Good workability, PA1 4) Good in step coverage PA1 5) Good in gap fill property, PA1 6) Low water absorption PA1 7) Capability of coping with a damascene process (embedded wiring). PA1 (1) An insulating film for a semiconductor device used as an interlayer insulating film of a semiconductor device, the insulating film consisting essentially of poly-.alpha.,.alpha.-difluoroparaxylylene and having a relative dielectric constant of from 2.1 to 2.7. PA1 (2) An insulating film for a semiconductor device used as an interlayer insulating film of a semiconductor device, the insulating film consisting essentially of poly-.alpha.,.alpha.-difluoroparaxylylene and exhibiting a step coverage of from 0.4 to 0.9. PA1 (3) An insulating film for a semiconductor device capable of being filled in a gap, the insulating film consisting essentially of poly-.alpha.,.alpha.-difluoroparaxylylene, having a ratio (D/L) of a depth (D) and an opening width (L) of 1 or more. PA1 (4) An insulating film for a semiconductor device as in one of the constitutions (1) to (3), wherein a shape of the insulating film is capable of being patterned by irradiation of oxygen plasma. PA1 (5) A semiconductor device comprising a semiconductor substrate having thereon at least two conductive layers through an interlayer insulating film, the interlayer insulating film is an insulating film as in one of the constitutions (1) to (4).
However, no material has been known that has a low dielectric constant and satisfies all the characteristics required for an interlayer insulating film of a semiconductor device.